The present invention relates generally to a roller assembly of an undercarriage of a work machine, and more particularly to a roller assembly of an undercarriage assembly having an integrated retainer and thrust bushing and method for making the same.
A work machine, such as a track-type tractor or excavator, is typically supported and propelled by a pair of undercarriage assemblies, each one of which includes an endless drive track chain having a plurality of interconnected articulating components or links. The undercarriage assembly typically also includes a drive sprocket, one or more idler wheels, a number of lower track rollers, and a carrier roller around each of which the drive track chain is entrained or otherwise advanced.
Over time as a result of extended operation of the work machine, a number of the components associated with the undercarriage assembly, such as the idler rollers, the track rollers, and the carrier roller begin to wear thereby necessitating repair thereof. However, repair of such components is often impractical since heretofore designed idler rollers, track rollers, and carrier rollers are generally mechanically complex thereby creating undesirable amounts of machine downtime during periods of repair. One such heretofore designed carrier roller is shown in U.S. Pat. No. 4,695,102 issued to Crotti. The carrier roller disclosed in Crotti, amongst other things, includes roller bearing assemblies for absorbing radial and axial thrust loads. However, use of such roller bearing assemblies adds to the mechanical complexity of the carrier roller thereby increasing the cost and time associated with repair thereof.
In an effort to avoid the complexity and cost associated with repair of idler rollers, track rollers, and carrier rollers, certain manufactures have chosen to make such components xe2x80x9cdisposablexe2x80x9d. In other words, when the component has worn to the point of needing repair, the idler roller, track rollers, or carrier roller is removed from the work machine and thereafter discarded. Thereafter, a replacement idler roller, track roller, or carrier roller is then installed on the machine. It should be appreciated that in the case of when a component is designed to be disposed, in lieu of repaired, it is even more desirable to produce the component in a cost efficient manner thereby reducing operation costs associated with the work machine.
What is needed therefore are undercarriage components which overcome one or more of the above-mentioned drawbacks. What is also needed are undercarriage components which are less mechanically complex relative to heretofore designed components. What is moreover needed is a method of manufacturing undercarriage components which is less expensive and less complex relative to heretofore utilized manufacturing methods.
In accordance with one embodiment of the present invention, there is provided a roller assembly for an undercarriage of a work machine. The roller assembly has a roller rim having central passage defined therein. The roller assembly also has a roller shaft positioned in the central passage of the roller rim. Moreover, the roller assembly has a retainer secured to the roller rim so as to retain the roller shaft in the central passage. The retainer is prepared by a process including the steps of (i) arranging a first type of metal powder in a first predetermined location, (ii) arranging a second type of metal powder in a second predetermined location, the second type of metal powder being different than the first type of metal powder, and (iii) sintering both the first type of metal powder and the second type of metal powder.
In accordance with another embodiment of the present invention, there is provided a method of manufacturing a roller assembly for an undercarriage of a work machine. The method has the step of arranging a first type of metal powder in a first predetermined location. The method also has the step of arranging a second type of metal powder in a second predetermined location, the second type of metal powder being different than the first type of metal powder. The method further has the step of sintering both the first type of metal powder and the second type of metal powder so as to form a retainer. Moreover, the method has the step of positioning the retainer in a central passage defined in a roller rim.
In accordance with yet another embodiment of the present invention, there is provided an undercarriage assembly of a work machine. The undercarriage assembly has a drive sprocket. The undercarriage assembly also has a roller assembly having (i) a roller rim having central passage defined therein, (ii) a roller shaft positioned in the central passage of the roller rim, and (iii) a retainer secured to the roller rim so as to retain the roller shaft in the central passage, the retainer being prepared by a process including the steps of (a) arranging a first type of metal powder in a first predetermined location, (b) arranging a second type of metal powder in a second predetermined location, the second type of metal powder being different than the first type of metal powder, and (c) sintering both the first type of metal powder and the second type of metal powder. The undercarriage assembly also has a drive track chain which is advanced around both the drive sprocket and the roller assembly.